Musicians may also want to plug in a MIDI controller, and the good news is that the plugKey enables you to do all of these things. Connecting over a Lightning cable, the it has a 5-Pin MIDI In port, while L/Mono and R line outs are on 1/4-inch jacks. There's an additional 1/8-inch mini headphones jack and a micro USB port for charging, plus a volume knob.

This is a proper interface rather than an 'adapter', then, which is reflected in its £90/$100 price tag. It does far more than simply let you listen to music and charge your phone at the same time, though, and has plenty to offer not only to iPhone 7 owners, but also to users of other iOS devices.